US 2008/044912 (Patent Document 1) discloses a blood coagulation analyzer in which a light irradiation unit applies light having different wavelengths for blood coagulation analysis onto a measurement container installed in a container installation section, and a light reception part detects light transmitted through the measurement container. The light irradiation unit in Patent Document 1 includes a halogen lamp that is a broadband light source and a filter unit that holds optical filters having different transmittance wavelengths along the circumference. The filter unit is configured to rotate the optical filters around the central axis and to sequentially dispose the optical filters on an optical path from a light source. Thus, the light irradiation unit sequentially applies light having different wavelengths onto the measurement container installed in the container installation section. The light having the different wavelengths is used to measure a sample in different measurement items.